Odds to Decimal
American odds are converted to decimal: positive odds = (american / 100) + 1, negative odds = (100 / |american|) + 1. Fractional odds: fractional + 1.
Sports Betting
About No Vig Odds Calculator
Remove the bookmaker margin from American, Decimal, or Fractional odds to reveal fair probabilities and fair odds for 2-way and 3-way markets.
No VigFair OddsImplied ProbabilityArbitrageSports Betting
About this calculator
What this does
Removes the built-in bookmaker margin (vigorish) from American, Decimal, or Fractional betting odds to reveal the true implied probabilities and fair market odds. It supports both 2-way markets like moneyline bets and 3-way markets like win-draw-wins. The calculator also detects arbitrage opportunities when the total implied probability drops below 100%.
Who it is for
Sports bettors, odds traders, and analytics enthusiasts who want to understand the true probability behind posted odds, compare fair lines across sportsbooks, or identify arbitrage opportunities in any sport.
How it works
Enter the odds for each outcome (2 or 3 outcomes depending on the market), and the calculator converts them to decimal format, then to implied probabilities. It sums all implied probabilities to find the overround (the vig). Each implied probability is divided by the total to get the no-vig (true) probability, which is then converted back into fair American and Decimal odds. If the total is under 100%, an arbitrage alert is shown.
Limitations
Assumes the market is efficient and that the bookmaker's margin is distributed proportionally across all outcomes—not uneven shading. Does not account for line movement, closing line value, or sportsbook-specific adjustments like reduced juice or promo pricing.
Formula
Implied Probability
Each outcome's decimal odds are inverted to find the bookmaker's implied probability. impliedProbability = 1 / decimalOdds
No-Vig (True) Probability
Each implied probability is divided by the total overround to remove the bookmaker margin. trueProbability = impliedProbability / totalImpliedProbability
Fair Odds and Vig Percentage
Fair decimal odds are the inverse of the no-vig probability. vigPercentage = (totalImpliedProbability - 1) × 100. A negative vig means arbitrage.
How it works
Step 1
Select the odds format
Choose American (+150, -200), Decimal (2.50), or Fractional (3/2). The calculator auto-detects the format as you type if you leave it on the current setting.
Step 2
Choose the market type
Select 2-way for two-outcome markets (moneyline) or 3-way for three-outcome markets (win-draw-win or spread + moneyline).
Step 3
Enter outcome labels and odds
Customize each outcome label (e.g., Team A, Team B) and paste or type the odds. The calculator auto-detects the format for each entry.
Step 4
Review the fair odds output
The results panel shows each outcome's implied probability, no-vig true probability, and fair American and Decimal odds side by side.
Step 5
Check for arbitrage
If the total implied probability is below 100%, an arbitrage alert appears with your guaranteed profit edge.
Step 6
Share or download results
Use the Share button to copy a URL with your current odds state, or Download to save a formatted HTML report of the full analysis.
Reference ranges
Vig Percentage
Standard sportsbook vig is 3-5% for NFL and NBA moneylines, 4-6% for MLB, and 5-8% for soccer 3-way markets. Reduced juice books offer 1-2% vig.
Total Implied Probability
A typical 2-way market has total implied probability of 102-105%. 3-way markets often run 105-110%. Below 100% is an arbitrage opportunity.
Arbitrage Edge
Usable arbitrage opportunities are rare and typically offer 0.5-2% edge. Above 3% is exceptional but requires quick execution before lines adjust.
Fair Odds Shift
Removing vig typically shifts odds by 5-15 cents on the American line for standard markets. Heavier vig (e.g., 8%+) produces larger shifts.